Failure to start casting part.end error.

[phyck]

I sometimes get following part.end error when I try casting a local video file:
command: castnow video.mkv --subtitles subtitle.srt --subtitles-scale 1.4

`/usr/local/lib/node_modules/castnow/utils/serve-mp4.js:22
var chunksize = (part.end - part.start) + 1;
^

TypeError: Cannot read property 'end' of undefined
at module.exports (/usr/local/lib/node_modules/castnow/utils/serve-mp4.js:22:25)
at Object.fn (/usr/local/lib/node_modules/castnow/plugins/localfile.js:53:5)
at loop (/usr/local/lib/node_modules/castnow/node_modules/router/index.js:43:11)
at Server.route (/usr/local/lib/node_modules/castnow/node_modules/router/index.js:50:3)
at Server.emit (events.js:314:20)
at parserOnIncoming (_http_server.js:779:12)
at HTTPParser.parserOnHeadersComplete (_http_common.js:122:17)
`

Casting the same video with vlc works, so file is not corrupted.